| Allyl alcohol is an important chemical material.However,since allyl alcohol and water can form a minimum azeotrope,the special distillation is necessary.The vapor liquid equilibrium data and the liquid liquid equilibrium data are important component of the phase equilibrium data,and have extensive application in the design of salt distillation and liquid liquid extraction process respectively.Therefore,in order to obtain the basic data for the separation of allyl alcohol and water.The vapor liquid and liquid liquid equilibrium related to allyl alcohol and water were researched.To separate the azeotrope of allyl alcohol and water by salt distillation.Owing to the system of allyl alcohol and water formed an azeotrope at x=0.451,three salts calcium chloride,calcium nitrate and magnesium nitrate were selected to break the azeotrope.The vapor-liquid equilibrium(VLE)data for the systems allyl alcohol+water,allyl alcohol+water+calcium nitrate,allyl alcohol+water+calcium chloride and allyl alcohol+ water+magnesium nitrate were measured at pressure of 101.3 kPa.The results indicated that the relative volatility of allyl alcohol to water increased by adding the salts.With increasing the concentrations of the salts,the azeotropic point of the system allyl alcohol+water moved.When the concentrations of calcium chloride and magnesium nitrate were 0.10,0.15,respectively,the azeotropic point was broken.The effect of salts on the azeotropic point of the system allyl alcohol+water follows the order;calcium chloride>magnesium nitrate>calcium nitrate.Moreover,the experimental VLE data were correlated by the NRTL model.All the root-mean-square deviations for the temperature(T)and the mole fraction of the vapor phase(y1)between the measured and calculated data were less than 0.26 K and 0.005,respectively.Meanwhile,the binary interaction parameters of the NRTL model were regressed.The liquid-liquid extraction was also selected to the azeotropic system of allyl alcohol and water.In this work,three organic solvents(isobutyl acetate butyl acetate or butyl propionate)were selected to extract allyl alcohol from the aqueous solution due to their low cost,low toxicity and low solubility in aqueous phase.The liquid-liquid equilibrium data for the systems of isobutyl acetate+allyl alcohol+ water,butyl acetate+allyl alcohol+water and butyl propionate+allyl alcohol+water was investigated in the temperature(298.15 K and 313.15 K)under the pressure of 101.3 kPa.The Othmer-Tobias,Hand and Bachman equations were used to check the reliability of the data and the values of R2 were greater than 0.9893,which shows that the reliability of the experimental data is higher.Meanwhile,the distribution coefficient and selectivity factor were calculated.And butyl propionate is more appropriate to separation of allyl alcohol and water by extraction distillation.Furthermore,the mutual solubility of both phases increased with rising temperature and low temperature is useful for extraction.Moreover,the binary interaction parameters were obtained by correlating the equilibrium data with the UNIQUAC and NRTL models.To recover the extractive agents by distillation,the isobaric vapor-liquid equilibrium(VLE)data for the systems allyl alcohol+isobutyl acetate,allyl alcohol+butyl acetate and allyl alcohol+butyl propionate were measured at the pressure of 101.3 kPa.The VLE data show that there is no azeotropic behavior in three binary systems.The thermodynamic consistency of the measured VLE data was validated by the Herington,van Ness,infinite dilution and pure component consistency test.Moreover,the NRTL,Wilson and UNIQUAC activity coefficient models were applied to correlate the experimental VLE data.All the calculated results showed agreement with the measured VLE data.Meanwhile,the binary interaction parameters of the NRTL,Wilson and UNIQUAC were regressed.Furthermore,the UNIFAC model was employed to predict the VLE data for the three binary systems,and the better prediction results were presented. |
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